Scientist and journalist Dr. Michael Guillen, most known for being the former science editor for ABC News and for guest appearances on "Good Morning America," will preach the Easter message Sunday at the Crystal Cathedral, church representatives announced Wednesday.

Guillen comes from a family of ministers and is also popular for being an award-winning scientist who is at the same time a die-hard believer. A three-time Emmy Award winner and bestselling author, he hosted shows on The History Channel and PBS. He has a Ph.D. degree in physics, mathematics and astronomy from Cornell University and was an instructor at Harvard University. As the son and grandson of Pentecostal ministers, Guillen felt called to full-time ministry in 2008, following an appearance on the "Hour of Power," Crystal Cathedral's signature televised service.

Guillen, who is the author of the book Can a Smart Person Believe in God?, will preach a message about the resurrection called, "Never Say Die."

Crystal Cathedral, the popular Orange County megachurch, has been undergoing major staff changes after its founder, Robert H. Schuller, quit the board of directors and left the church a month ago, followed by other family members who were all holding top positions within the ministry. The board is still in the search for a proper replacement for its senior pastor, Sheila Schuller Coleman, who left with a part of the congregation to found her own church, Hope Center of Christ. The role has been temporarily filled by Lawrence Wilkes. John Charles is the new CEO and president of Crystal Cathedral Ministries.

"We're thrilled to have him," Charles said about Guillen guest pastoring. "Our church has had a long-time relationship with him and his family."

Sunday morning services will be held at 9:30 a.m. and 11 a.m., with music from John Tebay, the temporary choir director, and Marc Riley directing the orchestra, as well as Jason Catron and Debby Tebay providing the vocal, church representatives said. At 6 p.m. Sunday the service will be led by the Rev. Bill Bennett.

Crystal Cathedral, which is known for its eye-catching glass building in Garden Grove, Calif., was forced to file for Chapter 11 bankruptcy in 2010, and to sell its signature property to the Orange County Roman Catholic diocese. The congregation is allowed to stay for three years since the escrow closed, before having to find a new location.